Portion of a motorcycle cylinder head



FIG. 1 is a perspective view of a portion of a motorcycle cylinder head showing my new design; and,

FIG. 2 is a side view of the motorcycle cylinder head shown in FIG. 1.

The uneven broken line, immediately adjacent to the shaded areas, represents the bounds of the claimed design. All other uneven broken lines represent the remaining portion of the motorcycle cylinder head. The uneven broken line representations in FIGS. 1-2 are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a portion of a motorcycle cylinder head, as shown and described. 